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Metal halide perovskites have rapidly advanced the field of optoelectronic devices, especially for photovoltaic (PV) and light‐emitting diode (LED) fields with efficiencies comparable to those well‐established technologies. However, most of the reported perovskite devices are fabricated using lab‐scale solution‐processing methods. The thermal evaporation (TE) method, a mature technique widely used in the semiconductor industry, could be a promising alternative technology for large‐area and scale‐up fabrication. Moreover, the TE method is free of toxic solvent, enables easy control of film thickness, and is compatible with existing industry. This review first presents the fundamentals of the TE method, with an emphasis on the growth mechanism of perovskite films. This is followed by the progress of thermally evaporated perovskite‐based optoelectronic devices, especially solar cells and light‐emitting diodes. Last, the device‐oriented design principles via TE technology are summarized and future development opportunities are overviewed. [ABSTRACT FROM AUTHOR]

Perovskite light‐emitting diodes (PeLEDs) have attracted great research interests considering their excellent luminescent properties and solution processability. Despite rapid advances of green‐, red‐, and near‐infrared‐emitting PeLEDs, blue‐PeLEDs, as an essential part for full‐color display and solid‐state lighting, still remain challenging due to their low efficiency and spectral instability. Here, reported are spectrally stable blue‐PeLEDs biased by an alternating voltage. First, 2‐phenoxyethylamine‐passivated CsPbBrxCl3−x is obtained as a blue emitter with a record photoluminescence quantum yield of 88%. Subsequently, constructed and optimized are pure blue‐emitting PeLEDs exhibiting electroluminescence (EL) at 468 nm with a high external quantum efficiency of 0.71%. Furthermore, driven are the devices by square‐wave alternating voltage and stabilized are the EL spectra for 12 h by suppressing the detrimental halide migration during operation. It is believed that this work provides an alternative way for the spectrally stable mixed halide blue PeLEDs. [ABSTRACT FROM AUTHOR]